Superpolished Stainless Steel Optics and Mirrors

Superpolished metal surfaces approaching 5 Angstrom Ra finish, without using polished
electroless nickel plating are now possible for use as mirrors. Valley's process of
optically polishing these pure metal substrates and wafers enables materials such as
304SS, 316SS, 430SS and 17-4 PH (Custom 630) Stainless Steel, to be used as mirrors.

Physical properties of 17-4 PH Stainless Steel which are important for critical
applications include: